The invention discloses a preparation process of
fermentation of non-
ammonia-smell natto, which includes the steps of: 1) fine selection of soya beans; 2) soaking; 3)
steaming; 4) quick cooling; 5)
inoculation and
fermentation; 6) standing post-maturation and storage of finish product. In the step 3), the soya beans are steamed without necessity of high temperature, so that loss on amino acids andsaccharides due to
Maillard reaction is prevented and color deepening of the finish product is avoided. Generally, the
steaming operation is carried out under 0.08-0.1 MPa for 30-40 min, and if the soya beans are crushed, the time only lasts for 7-8 min. The method simplifies the production
route of the natto and improves production efficiency of enterprises, thus effectively improving convenience. Meanwhile, in the method,
bacillus natto-
lactobacillus acidophilus fusant strain is used instead of the
bacillus natto strain, so that on the basis of maintaining the natto
kinase activity to be not changed basically, content of
amino acid nitrogen in the natto is increased. The natto is free of pungent
ammonia smell, has a gentle mouth feel and reduced
irritation, and has no difference from traditional natto in
wire drawing.